(509r) Supercritical Fluid Solvent Effects on Activity and Selectivity in Fischer Tropsch Synthesis

Our earlier work has shown that using a supercritical fluid reaction media for Fischer Tropsch Synthesis (FTS) gives better activity maintenance than gas-phase FTS. To further study this observation, a series of gas-phase FTS runs were carried out separated by periods of washing the catalyst with super-critical hexane. The supercritical hexane washings restored some of the lost activity and selectivity observed during gas phase operation. The supercritical hexane washings also produced some changes in selectivity that do not correspond to the effect of time-on-stream during gas phase operation.

Supercritical hexane phase FTS was also performed in this study resulting in slightly higher conversion, lower methane selectivity, and a shift in oxygen disposal from carbon dioxide to water in comparison to gas-phase FTS. Data on the effect of the reaction media (hexanes, helium, and a mixture of the two) on the FTS process will be presented.